B1388

DTC Troubleshooting: B1388

DTC B1388:

Power Tailgate Motor Circuit Malfunction

1. Open the tailgate.

2. Close the tailgate automatically with the keyless transmitter or power tailgate inside switch.

3. Turn the ignition switch to LOCK (0) and then back to ON (II), or press the engine start/stop button to select the OFF mode and then the ON mode.

4. Clear the DTCs with the HDS.

5. Check for DTCs with the HDS.

Is DTC B1388 indicated?

YES -

Go to step 6.

NO -

Intermittent failure, the system is OK at this time. Check for loose or poor connections between the power tailgate control unit and the drive unit.�

6. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.

7. Disconnect power tailgate control unit connector A (5P).

8. Disconnect drive unit connector A (2P).

9. Check for continuity between body ground and power tailgate control unit connector A (5P) terminals No. 3 and No. 5 individually.





Is there continuity?

YES -

Repair a short to ground in the wire.�

NO -

Go to step 10.

10. Reconnect drive unit connector A (2P).

11. Connect battery power to power tailgate control unit connector A (5P) terminal No. 3 (or No. 5) and ground the terminal No. 5 (or No. 3).





12. Check the power tailgate motor operation.

Does the motor run normally?

YES -

Go to step 13.

NO -

Faulty power tailgate motor, replace the drive unit Service and Repair.�

13. Disconnect power tailgate control unit connector B (20P).

14. Disconnect power tailgate drive unit connector B (8P).

15. Check for continuity between body ground and power tailgate control unit connector B (20P) terminals No. 1 and No. 2 individually.





Is there continuity?

YES -

Repair a short to ground in the wire.�

NO -

Go to step 16.

16. Reconnect power tailgate drive unit connector B (8P).

17. Connect battery power to power tailgate control unit connector B (20P) terminal No. 1 and ground the terminal No. 2. Check for clutch operation.





Can you hear the clutch operate?

YES -

Go to step 18.

NO -

Faulty power tailgate clutch, replace the power tailgate drive unit Service and Repair.�

18. Measure the voltage between power tailgate control unit connector A (5P) terminal No. 2 and body ground.





Is there battery voltage?

YES -

Go to step 19.

NO -

Check the No. 6 (40 A) fuse in the auxiliary under-hood fuse/relay box. If the fuse is OK, check for an open or high resistance in the wire between the auxiliary under-hood fuse/relay box and the power tailgate control unit.�

19. Measure the voltage between power tailgate control unit connector B (20P) terminal No. 12 and body ground.





Is there battery voltage?

YES -

Go to step 20.

NO -

Check the No. 15 (20 A) fuse in the auxiliary under-hood fuse/relay box. If the fuse is OK, check for an open or high resistance in the wire between the auxiliary under-hood fuse/relay box and the power tailgate control unit.�

20. Check for continuity between body ground and power tailgate control unit connector A (5P) terminals No. 1 and No. 4 individually.





Is there continuity?

YES -

Replace the power tailgate control unit Service and Repair.�

NO -

NO-Repair an open or high resistance in the ground wire or poor ground (G603).�